Graphical user interface for indicating device failover

ABSTRACT

A computer-implemented method and apparatus for indicating a failover data path in a graphical user interface environment is provided. The method includes graphically displaying at least one source device; graphically displaying at least one target device; graphically displaying a first data path between at least one source device and at least one target device; and in response to a failure in the first data path: graphically indicating the failure in the first data path; and graphically displaying a failover data path.

BACKGROUND OF THE INVENTION

[0001] Many modern computer systems, particularly enterprise-class systems, are provided with redundant components to provide continuous uptime in the event that one of the system's components fails. In many such systems, the redundancy can be provided by including a pair of identical components which perform the same function in parallel. In the event that one of the redundant components fails, the other component will perform the function alone. This transition from one component to another can be referred to as a “failover.” In other systems, the redundant component is treated as a spare component and is not utilized until after the primary component fails.

[0002] Storage systems, for example, may be provided with dual data paths for receiving I/O data from an application host. One such system is the StorEdge T3 Array** sold by Sun Microsystems, Inc., of Palo Alto, Calif. In the event that one of the data paths fails, due to a failure in, for example, the host adapter card on the application host system, the Fibre Channel (“FC”) cable, or FC port on the StorEdge T3 Array, the other data path will handle all of the I/O traffic with the host application.

[0003] Existing storage systems can monitor redundant data paths and automatically manage the failover to a redundant data path in the event of a failure. However, when a component in these storage systems fails, the system may lose its redundancy protection. Therefore, if the corresponding failover component subsequently fails and there are no other redundant components available, the entire system may fail. Systems which simply manage the failover to the redundant data path but do not adequately warn the system operator of the failure may be left in a non-redundant state for an extended period of time. This increases the chances that the failover component will also fail before the first failed component is replaced. Accordingly, it may be desirable to indicate the first failure to a user in time to enable the user to take steps to replace the failed component promptly before any further failures occur.

[0004] In addition, it may also be desirable to warn the user of the failure in an immediately apparent way. Some systems may record the failure in an error log. This error log may be easily accessible to the system operator, but it is unlikely that the operator would review the error log without a more prominent warning. Furthermore, a textual message on a computer screen may not have sufficient visibility to alert an inattentive operator.

BRIEF SUMMARY OF THE INVENTION

[0005] In accordance with embodiments of the present invention, a computer-implemented method of indicating a failover data path in a graphical user interface environment is provided. The method comprises: graphically displaying at least one source device; graphically displaying at least one target device; graphically displaying a first data path between at least one source device and at least one target device; and in response to a failure in the first data path: graphically indicating the failure in the first data path; and graphically displaying a failover data path. This graphical display of the components of the computer system and the graphical indication of the failure in the first data path can be provide a more effective way of warning a system operator that the system has entered a failover state. Instead of a simple text message stating that the first data path has failed, this failure and subsequent failover to the second data path can be graphically displayed to thereby improve visibility to the system operator. This may result in a faster response by the user to replace the failed component.

[0006] In accordance with further embodiments of the present invention, an apparatus for managing the display of a plurality of data paths in a graphical user interface environment is provided. The apparatus comprises: a memory having program instructions; a processor configured to use the program instructions to graphically display at least one source device, graphically display at least one target device, graphically display a first data path between at least one source device and at least one target device, and in response to a failure in the first data path: graphically indicate the failure in the first data path and graphically display a failover data path.

[0007] In accordance with yet further embodiments of the present invention, a method of operating a storage system is provided. The method comprises: transmitting data from at least one application host to at least one storage system along a first data path; graphically displaying at least one component of at least one application host in a graphical user interface environment; graphically displaying at least one component of at least one storage system in the graphical user interface environment; and graphically displaying the first data path in the graphical user interface environment. In response to a failure in the first data path, the method further comprises: transmitting data from the application host to the storage system along a failover data path; graphically indicating the failure in the first data path in the graphical user interface environment; and graphically displaying the failover data path in the graphical user interface environment.

[0008] In accordance with yet further embodiments of the present invention, a computer-readable medium containing instructions for indicating a failover data path in a graphical user interface environment is provided. The instructions cause operations to be performed comprising: rendering a graphical representation of at least one source device on a computer display; rendering a graphical representation of at least one target device on the computer display; rendering a graphical representation of a first data path between at least one source device and at least one target device; and in response to a failure in the first data path: graphically indicating the failure in the first data path; and rendering a graphical representation of a failover data path.

[0009] Other features and aspects of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the features in accordance with embodiments of the invention. The summary is not intended to limit the scope of the invention, which is defined solely by the claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 shows a functional block diagram of a storage system in accordance with embodiments of the present invention.

[0011]FIG. 2 shows a functional block diagram of an application host in accordance with embodiments of the present invention.

[0012]FIG. 3 shows a flowchart of a method for indicating a failover data path in accordance with embodiments of the present invention.

[0013] FIGS. 4-5 show exemplary Graphical User Interface (GUI) panels in accordance with embodiments of the present invention.

[0014]FIG. 6 shows a functional block diagram of a storage system in accordance with other embodiments of the present invention.

[0015] In the following description, reference is made to the accompanying drawings which form a part thereof, and which illustrate several embodiments of the present invention. It is understood that other embodiments may be utilized and structural and operational changes may be made without departing from the scope of the present invention. The use of the same reference symbols in different drawings indicates similar or identical items.

DETAILED DESCRIPTION OF THE INVENTION

[0016] Some portions of the detailed description which follows are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits that can be performed on computer memory. A procedure, computer-executed step, logic block, process, etc., are here conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those utilizing physical manipulations of physical quantities. These quantities can take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. These signals may be referred to at times as bits, values, elements, symbols, characters, terms, numbers, or the like. Each step may be performed by hardware, software, firmware, or combinations of any of these.

[0017]FIG. 1 is a block diagram that illustrates an exemplary arrangement in which embodiments of the present invention may be implemented. As shown in FIG. 1, a storage system 100 stores and retrieves data from one or more applications 105 running on application host 104. This data can be stored in one of two storage units 102 a-102 b provided in storage system 100.

[0018] Application host 104 may be any of a number of computer systems, such as, for example, a UNIX server or a computer running the Windows NT or Windows 2000 operating systems.** One embodiment for application host 104 is described in greater detail in the text below corresponding to FIG. 2. Application host 104 may be provided with two interfaces 106 a-106 b, which are coupled to data ports 112 a, 112 b in storage system 100 via connections 130 a, 130 b, respectively. Interfaces 106 a-106 b, may be, for example, Fibre Channel-Arbitrated Loop (“FCAL”) host bus adapter cards which receive data from a local bus on application host 104 and transmit the data to storage system 100.

[0019] In the embodiment shown, storage units 102 a-102 b comprise two substantially identical controller units which are paired in a partner group to provide redundant controllers and redundant data and management paths. In other embodiments, the number and extent of redundant components within storage system 100 may vary.

[0020] Each storage unit 102 includes a controller 110 coupled to a pair of unit interconnect cards (“UIC”) 116, 118. Each UIC 116, 118 is coupled to an array 120 of storage devices 122. Storage devices 122 may be, for example, hard disk drives or any other devices for storing data in non-volatile form, such as optical disks, floppy disks, or tape storage. In addition, UIC 116 a in storage unit 102 a can also be coupled via connection 150 to UIC 116 b in storage unit 102 b. This enables data received by storage unit 102 a to be transmitted from UIC 116 a to UIC 116 b in storage unit 102 b to be stored in storage devices 122 b. This can be used to increase data throughput to storage devices 122 b and/or to enable storage unit 102 a and connection 150 to serve as a failover data path in the event of failure or other cessation of the primary data path to storage devices 122 b through controller 110 b.

[0021] Controller 110 may provide cache, RAID management, administration, diagnostics, and external interfaces for storage unit 102. In other embodiments, the functions performed by controller 110 may vary. For example, in some embodiments, controller 110 may provide only simple interfacing between application host 104 and storage devices 122. In the embodiment shown, controller 110 is provided with a data port 112 to provide connectivity with application host 104 and an administration port 114 to provide connectivity with a management host 124. Administration port 114 may be, for example, an Ethernet port coupled to management host 124 via network connection 140. In this arrangement, application host 104 generates the data to be stored in storage system 100, while management host 124 enables a user to perform various management and monitoring tasks on storage system 100.

[0022]FIG. 2 is a block diagram that illustrates one embodiment of application host 104 of FIG. 1. Application host 104 includes a bus 202 or other communication mechanism for transmitting data, and a processor 204 coupled with bus 202 for processing information. Application host 104 also includes a memory 206, which can be a random access memory (RAM) or other dynamic storage device, coupled to bus 202 for storing information and instructions to be executed by processor 204. Memory 206 also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by processor 204. Application host 104 further includes a read only memory (ROM) 208 or other static storage device coupled to bus 202 for storing static information and instructions for processor 204. A storage device 210, such as a computer-readable magnetic disk or optical disk, can be provided and coupled to bus 202 for storing information and instructions, such as application(s) 105.

[0023] Application host 104 may be coupled via bus 202 to a display 212, such as a cathode ray tube (CRT) or liquid crystal display (LCD), for displaying information to a computer user. An input device 214, including alphanumeric and other keys, can be coupled to bus 202 for communicating information and command selections to processor 204. It is possible to implement methods consistent with the principles of the present invention on other devices comprising at least a processor, memory, and a display, such as a personal digital assistant.

[0024] Application host 104 also includes interfaces 106 a-106 b coupled to bus 202. As described above, interfaces 106 a-106 b may be used to provide I/O connectivity between application host 104 and storage system 100. Application(s) 105 running on application host 104 may transmit data via interfaces 106 a-106 b to be stored on the storage devices 122 a-122 b of storage units 102 a-102 b. In one embodiment, data intended to be stored in storage unit 102 a is transmitted from interface 106 a over connection 130 a to data port 112 a in controller 110 a. The data then passes through either UIC 116 a or UIC 118 a to be stored on one or more of the storage devices 122 a. This path between application(s) 105 and storage devices 122 a comprises a first data path. Similarly, data intended to be stored in storage unit 102 b is transmitted out of interface 106 b over connection 130 b to data port 112 b in controller 110 b. The data then passes through either UIC 116 b or UIC 118 b to be stored on one or more of storage devices 122 b. This path comprises a second data path. Therefore, application host 104 has two independent data paths with storage system 100.

[0025] In the event that the first data path fails, a failover data path between application(s) 105 and storage devices 122 a can be established. In one embodiment, data that would normally be routed out of interface 106 a to controller 110 a is instead routed out of interface 106 b to controller 110 b and then to UIC 116 b. This data can then be transmitted via connection 150 to UIC 116 a and then stored onto storage devices 122 a. Alternatively, the data can be transmitted from controller 110 b to UIC 118 b, and then be transmitted over connection 152 to UIC 118 a.

[0026] Many modern computer systems employ graphical user interfaces for displaying textual and graphical information to the user. Such graphical interfaces can facilitate computing by providing a quickly and easily comprehensible way in which to convey information to the user. It may be desirable to provide a graphical display to a user to indicate the status of the multiple data paths and to further indicate the presence of a failover data path.

[0027]FIG. 3 shows a flowchart of a method for indicating a failover data path in accordance with embodiments of the present invention. In step 301, at least one source device and at least one target device are graphically displayed in a Graphical User Interface (GUI) environment. In step 302, a first data path between at least one source device and at least one target device is graphically displayed. Next, in step 303, if a failure in the first data path is detected, the failure in the first data path is graphically indicated in step 304. Finally, in step 305, a failover data path is graphically displayed.

[0028]FIGS. 4 and 5 show exemplary GUI panels 400, 500 which may be generated by application host 104 in FIGS. 1-2 in accordance with embodiments of the present invention. In FIG. 4, two source device icons 402 a-402 b and two target device icons 404 a-404 b are graphically displayed. Source device icons 402 a-402 b correspond to interfaces 106 a-106 b and are displayed as graphical representations of two host bus adapter cards. Target device icons 404 a-404 b correspond to storage units 102 a-102 b and are displayed as graphical representations of the front portion of the physical enclosures for storage units 102 a-102 b. The graphical display can be provided on display 212.

[0029] In GUI panel 400, two data paths are also graphically displayed. The two data paths are shown as link 406 a connecting source device icon 402 a with target device icon 404 a, and link 406 b connecting source device icon 402 b with target device icon 404 b. The data paths can be visually distinguished in a variety of ways, such as, for example, by displaying colored segments, or by displaying an animated graphic. In the embodiment shown, links 406 a-406 b are graphically shown as lines having moving green portions 408 a-408 b which traverse the length of links 406 a-406 b to indicate that the data paths are active.

[0030]FIG. 5 shows an exemplary GUI panel 500 in which the failure in the first data path is graphically indicated. In panel 500, failed link 406 a is graphically shown as a dashed line connecting source device icon 402 a and target device icon 404 a. In addition, the moving green portion 408 a is omitted and can be replaced, for example, with a moving red portion. The failover data path is graphically shown as a link 410 having a moving green portion 412. When implemented in storage system 100, link 410 corresponds to either connection 150 or connection 152 and therefore is shown directly connecting target device icon 404 a with target device icon 404 b. In other embodiments, the failover data path can be shown in other ways, such as, for example, a link between source device icon 402 b and target device icon 404 a.

[0031] In the embodiments shown, GUI panels 400, 500 may be running on application host 104. The graphical display of the failover data path can be provided as part of an executable program which may perform various types of storage management tasks. In other embodiments, a separate management host 124 coupled to administration ports 114 a, 114 b via network connection 140 can be provided for performing storage management tasks, including the generation of GUI panel displays 400, 500 as described above. In these embodiments, the data being stored onto storage devices 122 is still transmitted from application host 104 via connections 130 a, 130 b to storage units 102 a, 102 b. In yet other embodiments, the graphical display of the failover data path may be provided on a browser application running on another computer system. Numerous variations are possible and contemplated.

[0032] While the invention has been described in terms of particular embodiments and illustrative figures, those of ordinary skill in the art will recognize that the invention is not limited to the embodiments or figures described. For example, the components that form the primary and target devices, the first and second data paths, and the failover data paths may vary. In some embodiments, a single application 105 transmits data to be stored on storage devices 122 a and storage devices 122 b. The source device in this case is application 105 and the target devices are storage devices 122 a-122 b, and the first and second data paths comprise the path taken by the data as it travels from application 105 to either storage devices 122 a or storage devices 122 b. In other embodiments, the data paths may comprise different portions of the path taken by data between the application 105 and the storage devices 122 a-122 b. For example, the first data path may be formed solely by the path from interface 106 a to data port 112 a. In other embodiments, the source device may comprise, for example, the entire application host 104, or one or more of the components thereof, such as application(s) 105 or interfaces 106 a-106 b. The target device may comprise, for example, the entire storage system 100, or one or more of the components thereof, such as data ports 112 a-112 b, controllers 110 a-110 b, UICs 116 a-116 b, 118 a-118 b, storage units 102 a-102 b, or individual storage devices 122 a-122 b. In various embodiments, the data paths may comprise any combination of the components connecting the source device(s) and the target device(s).

[0033] In the embodiment described above, storage units 120 a and 120 b are substantially identical partner pairs in storage system 100. In other embodiments, the two target devices need not be substantially identical, nor do they need to be components of a larger system. For example, the two target devices may be separate storage systems equipped to provide path failover for data being transmitted by host applications. In other embodiments, there may be only a single target device. FIG. 6 shows a functional block diagram of a storage system in which one or more applications 605 running on application host 604 transmit data to a single array 620 of storage devices 622 in storage system 600. Between application host 604, there are two data paths available between application(s) 605 and array 620. A first data path comprises interface 606 a, connection 630 a, data port 612 a in controller 610 a, and connection 632 a, and a second data path comprises interface 606 b, connection 630 b, data port 612 b in controller 610 b, and connection 632 b. In normal operation, both the first and second data paths may be used to transmit data, and in the event of a failure in the first data path, the second data path may then serve as the failover data path. In other embodiments, only the first data path is used in normal operation, and the second data path is reserved for failover use only. Numerous variations are possible and contemplated.

[0034] In the embodiment shown in FIG. 1, UIC 116 a, 118 a in storage unit 102 a transmit data to storage devices 122 a and also can be used to provide a failover data path for data to be stored in the other storage unit 102 in storage system 100. In other embodiments, these functions can be provided by separate components. For example, another interface may be provided in controller 110 a for coupling with storage unit 102 b in the event of failover. In yet other embodiments, interface 106 a may be coupled to both storage unit 102 a and 102 b to provide failover data transmission to either storage unit 102.

[0035] It is also noted that the data paths can provide bi-directional data flow. For example, in addition to transmitting data from application host 104 to be stored in storage system 100, the data paths can also be used to transmit data retrieved from storage devices 122 to application host 104.

[0036] The program logic described indicates certain events occurring in a certain order. Those of ordinary skill in the art will recognize that the ordering of certain programming steps or program flow may be modified without affecting the overall operation performed by the preferred embodiment logic, and such modifications are in accordance with the various embodiments of the invention. Additionally, certain of the steps may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above.

[0037] The foregoing description of the preferred embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Therefore, it should be understood that the invention can be practiced with modification and alteration within the spirit and scope of the appended claims. 

What is claimed is:
 1. A computer-implemented method of indicating a failover data path in a graphical user interface environment, said method comprising: graphically displaying at least one source device; graphically displaying at least one target device; graphically displaying a first data path between at least one source device and at least one target device; and in response to a failure in the first data path: graphically indicating the failure in the first data path; and graphically displaying a failover data path.
 2. The method of claim 1, wherein: said graphically displaying at least one source device comprises graphically displaying at least one component of at least one application host; and said graphically displaying at least one target device comprises graphically displaying at least one component of at least one storage system.
 3. The method of claim 1, wherein: said graphically indicating the failure in the first data path comprises eliminating the graphical display of the first data path.
 4. The method of claim 1, wherein: said graphically displaying the first data path comprises displaying a first link between at least one source device and at least one target device, and animating the first link to indicate that the first data path has not failed.
 5. The method of claim 4, wherein: said graphically indicating the failure in the first data path comprises one of the group consisting of: ceasing the display of the first link; displaying a red-colored portion on the first link; and displaying the first link using a broken line.
 6. The method of claim 1, further comprising: graphically displaying a second data path between at least one source device and at least one target device.
 7. The method of claim 6, wherein: said graphically displaying at least one source device comprises graphically displaying two source devices; said graphically displaying at least one target device comprises graphically displaying two target devices; said graphically displaying the first data path comprises graphically displaying the first data path between a first of the two source devices and a first of the two target devices; and said graphically displaying the second data path comprises graphically displaying the second data path between a second of the two source devices and a second of the two target devices.
 8. The method of claim 7, wherein said graphically displaying the two source devices comprises displaying a graphical representation of at least two host adapters; and said graphically displaying the at least two target devices comprises displaying a graphical representation of at least two storage units.
 9. The method of claim 7, wherein: said graphically displaying the failover data path comprises displaying a third link between the first target device and the second target device.
 10. The method of claim 9, wherein: said graphically displaying the failover data path further comprises animating the third link to indicate that the third link is being used as a failover path.
 11. An apparatus for managing the display of a plurality of data paths in a graphical user interface environment, comprising: a memory having program instructions; a processor configured to use the program instructions to: graphically display at least one source device; graphically display at least one target device; graphically display a first data path between at least one source device and at least one target device; and in response to a failure in the first data path: graphically indicate the failure in the first data path; and graphically display a failover data path.
 12. The apparatus of claim 11, wherein: said graphically displaying at least one source device comprises graphically displaying at least one component of at least one application host; and said graphically displaying at least one target device comprises graphically displaying at least one component of at least one storage system.
 13. The apparatus of claim 11, wherein: said graphically indicating the failure in the first data path comprises eliminating the graphical display of the first data path.
 14. The apparatus of claim 11, wherein: said graphically displaying the first data path comprises displaying a first link between at least one source device and at least one target device, and animating the first link to indicate that the first data path has not failed.
 15. The apparatus of claim 14, wherein: said graphically indicating the failure in the first data path comprises one of the group consisting of: ceasing the display of the first link; displaying a red-colored portion on the first link; and displaying the first link using a broken line.
 16. The apparatus of claim 11, further comprising: graphically displaying a second data path between at least one source device and at least one target device.
 17. The apparatus of claim 16, wherein: said graphically displaying at least one source device comprises graphically displaying two source devices; said graphically displaying at least one target device comprises graphically displaying two target devices; said graphically displaying the first data path comprises graphically displaying the first data path between a first of the two source devices and a first of the two target devices; and said graphically displaying the second data path comprises graphically displaying the second data path between a second of the two source devices and a second of the two target devices.
 18. The apparatus of claim 17, wherein said graphically displaying the two source devices comprises displaying a graphical representation of at least two host adapters; and said graphically displaying the at least two target devices comprises displaying a graphical representation of at least two storage units.
 19. The apparatus of claim 17, wherein: said graphically displaying the failover data path comprises displaying a third link between the first target device and the second target device.
 20. The apparatus of claim 19, wherein: said graphically displaying the failover data path further comprises animating the third link to indicate that the third link is being used as a failover path.
 21. A method of operating a storage system, comprising: transmitting data from at least one application host to at least one storage system along a first data path; graphically displaying at least one component of at least one application host in a graphical user interface environment; graphically displaying at least one component of at least one storage system in the graphical user interface environment; graphically displaying the first data path in the graphical user interface environment; and in response to a failure in the first data path: transmitting data from the application host to the storage system along a failover data path; graphically indicating the failure in the first data path in the graphical user interface environment; and graphically displaying the failover data path in the graphical user interface environment.
 22. The method of claim 21, wherein: said graphically indicating the failure in the first data path comprises eliminating the graphical display of the first data path.
 23. The method of claim 21, wherein: said graphically displaying the first data path comprises displaying a first link between at least one component of at least one application host and at least one component of at least one storage system, and animating the first link to indicate that the first data path has not failed.
 24. The method of claim 23, wherein: said graphically indicating the failure in the first data path comprises one of the group consisting of: ceasing the display of the first link; displaying a red-colored portion on the first link; and displaying the first link using a broken line.
 25. The method of claim 21, further comprising: transmitting data from at least one application host to at least one storage system along a second data path; and graphically displaying the second data path in the graphical user interface environment.
 26. The method of claim 25, wherein: said graphically displaying at least one component of at least one application host comprises graphically displaying two components of an application host; said graphically displaying at least one component of at least one storage system comprises graphically displaying two components of a storage system; said graphically displaying the first data path comprises graphically displaying the first data path between a first of the two components of the application host and a first of the two components of the storage system; and said graphically displaying the second data path comprises graphically displaying the second data path between a second of the two components of the application host and a second of the two components of the storage system.
 27. The method of claim 26, wherein said graphically displaying the two components of the application host comprises displaying a graphical representation of two host adapters; and said graphically displaying the two components of the storage system comprises displaying a graphical representation of two storage units.
 28. The method of claim 26, wherein: said graphically displaying the failover data path comprises displaying a third link between the first component of the storage system and the second component of the storage system.
 29. The method of claim 28, wherein: said graphically displaying the failover data path further comprises animating the third link to indicate that the third link is being used as a failover path.
 30. A computer-readable medium containing instructions for indicating a failover data path in a graphical user interface environment, wherein said instructions cause operations to be performed comprising: rendering a graphical representation of at least one source device on a computer display; rendering a graphical representation of at least one target device on the computer display; rendering a graphical representation of a first data path between at least one source device and at least one target device; and in response to a failure in the first data path: graphically indicating the failure in the first data path; and rendering a graphical representation of a failover data path.
 31. The computer-readable medium of claim 30, wherein: said rendering the graphical representation of at least one source device comprises rendering the graphical representation of at least one component of at least one application host; and said rendering the graphical representation of at least one target device comprises rendering the graphical representation of at least one component of at least one storage system.
 32. The computer-readable medium of claim 30, wherein: said graphically indicating the failure in the first data path comprises eliminating the graphical representation of the first data path.
 33. The computer-readable medium of claim 30, wherein: said rendering the graphical representation of the first data path comprises displaying a first link between at least one source device and at least one target device, and animating the first link to indicate that the first data path has not failed.
 34. The computer-readable medium of claim 33, wherein: said graphically indicating the failure in the first data path comprises one of the group consisting of: ceasing the display of the first link; displaying a red-colored portion on the first link; and displaying the first link using a broken line.
 35. The computer-readable medium of claim 30, wherein said instructions cause further operations to be performed, comprising: rendering a graphical representation of a second data path between at least one source device and at least one target device.
 36. The computer-readable medium of claim 35, wherein: said rendering the graphical representation of at least one source device comprises rendering the graphical representation of two source devices; said rendering the graphical representation of at least one target device comprises rendering the graphical representation of two target devices; said rendering the graphical representation of the first data path comprises rendering the graphical representation of the first data path between a first of the two source devices and a first of the two target devices; and said rendering the graphical representation of the second data path comprises rendering the graphical representation of the second data path between a second of the two source devices and a second of the two target devices.
 37. The computer-readable medium of claim 36, wherein said rendering the graphical representation of the two source devices comprises displaying the graphical representation of at least two host adapters; and said rendering the graphical representation of the at least two target devices comprises displaying the graphical representation of at least two storage units.
 38. The computer-readable medium of claim 36, wherein: said rendering the graphical representation of the failover data path comprises displaying a third link between the first target device and the second target device.
 39. The computer-readable medium of claim 38, wherein: said rendering the graphical representation of the failover data path further comprises animating the third link to indicate that the third link is being used as a failover path. 